The marriage between a son of the billionaire financier Sir James Goldsmith
and an heir to the Rothschild banking dynasty is over, amid claims that she
had begun living an “increasingly nocturnal” lifestyle that led to her
having an affair with an American rapper.

Ben Goldsmith had separated from his wife Kate earlier this year, but after a brief reconciliation their relationship ended last week with police being called after they had a confrontation over her late nights and secret romance with Jay Electronica.

The 31 year-old slapped his wife and kicked a child’s toy truck at her, later accepting a caution for assault.

He has now moved out of the family home in west London and fled to Italy with his mother Lady Annabel and his three children, and will now file for divorce.

“I’m pretty shell-shocked by everything. All I am thinking about now is my children,” Mr Goldsmith told the Mail on Sunday.

His estranged wife is believed to be saddened not only by their split but also by the fact that details have been released to the press, and is consulting lawyers. Meanwhile the rapper blamed for the marriage breakdown was due to arrive back at his London residence last night.

A spokesman for Mrs Goldsmith said in a statement: “Articles in today’s media contain false and inaccurate information which appears to have been given to the media in a deliberate attempt to damage Kate and her businesses as well as to deflect from the gravity of last week’s incident involving the police.

“Kate is devastated, she has had a very frightening time since she and her husband initially split five months ago, and this is just another sad development.

“Her main concern now is for her children who will remain with her at the family home.”

The couple come from two of the country’s most illustrious and wealthiest families and had appeared to enjoy an enviable life together.

Mr Goldsmith inherited an estimated £300million after the death of his father Sir James, who built up a £1.2billion fortune as a food magnate and then investor before becoming a vocal opponent of the European Union. His other children with his third wife are Zac, the environment activist and Tory MP, and Jemima, who married the Pakistani cricketer turned politician Imran Khan.

Meanwhile Mr Goldsmith’s wife, 29, inherited an £18m fortune after the death of her banker father, Amschel Rothschild, and is related to the Guinness brewery family on her mother’s side.

The couple have known each other since they were teenagers and were regulars in society publications such as Tatler before married young in September 2003, at a wedding attended by 600 guests. With homes in Kensington and Somerset, they now have three children.

Mr Goldsmith founded a green venture capital firm, Wheb Ventures, and recently produced an acclaimed documentary film about the West Indies cricket team, Fire in Babylon.

Last year there were tensions between the couple after Mr Goldsmith met the Barbadian pop star Rihanna at a party and posted a photo of her on Twitter with the caption “too hot”.

But it is his wife’s nascent career in the music business that is believed to have led to the breakdown of their marriage.

In 2010 Mrs Goldsmith set up a company called Roundtable Records, which has so far released just four singles by little-known bands.

The venture has led to her spending time at gigs and clubs in London as well as travelling to Los Angeles, while her husband remains in an office job and responsible for the school run.

“They’re leading very different lifestyles,” said one family friend. “He has to be at his desk at 8.15am and take the kids to school, but her lifestyle is increasingly nocturnal, going to clubs until the very late or early hours.”

It wasn’t until last autumn that Mrs Goldsmith got to know the rapper now blamed for the end of her marriage.

Jay Electronica, 35, was born Timothy Elpadaro Thedford and grew up in one of the poor areas of New Orleans that was destroyed by Hurricane Katrina.

He became an underground success in 2007 after recording a nine-minute song called Act I: Eternal Sunshine (The Pledge) that featured him rapping over a soundtrack taken from the film Eternal Sunshine of the Spotless Mind.

He became even better known in 2010 when he had a daughter with the singer Erykah Badu.

But despite becoming a protégé to the leading hip-hop mogul Jay-J, he has only released a handful of singles and his long-awaited first album is yet to be released.

Last October he visited London and wrote on Twitter afterwards a message of to “Kate”, among others, for having “opened my mind in ways it hadn't been for years, in just 2 weeks. I lov u”.

The following month he addressed a message on the social networking service to Mrs Goldsmith, her brother James, and Mr Goldsmith’s siblings Zac and Jemima.

He has described Mrs Goldsmith as one of his “direct points of contact” for press and business enquiries and gave her personal email address, while last month he posted a photo of her sitting in a helicopter.

The rapper also praised her husband’s film, writing on Twitter: “Fire in Babylon was Amazing! Job Well Done." Mr Goldsmith replied: “So happy you loved it Jay.”

More recently Mr Goldsmith developed suspicions about the amount of time his wife was spending with Jay Electronica, and last Wednesday confronted her at their home after allegedly discovering incriminating text messages and emails on her smartphone.

During the row she is said to have confessed to having an affair with the rapper, and her husband was arrested after lashing out at her.

A Scotland Yard spokesman confirmed: “Police were called at 8am on Wednesday to reports of a domestic disturbance at an address in Kensington.

“Officers attended and a man, aged 31, was arrested on suspicion of causing actual bodily harm. He was taken to a west London police station and later accepted a caution.”

A friend of Mr Goldsmith’s said: “Ben is heartbroken, devastated and thoroughly miserable. He suspected Kate was cheating on him because she has been behaving increasingly erratically for some time.

“She is obsessed with this chap called Jay Electronica who is one of her clients. She is always on the phone to him and out with him until four or five in the morning most nights. Sometimes she even stays with him.

“Ben was paranoid about their friendship months ago, but when he confronted her about an affair earlier this year she denied it.

“Then last week he found a series of texts and email messages. They were very intense messages planning sexual liaisons.”

However sources close to Mrs Goldsmith insist that the couple’s marriage had been on the rocks for some time.

It is claimed that they separated at the start of the year, and it was during their three months apart that she had a brief fling with the rapper.

The couple then made a further attempt to make their marriage work but Mrs Goldsmith is now said to accept it is “game over”, and is unhappy that details of their split found their way to the press.

Mr Goldsmith is now staying with friends and will file for divorce on grounds of adultery.

The couple are expected to agree joint custody of their children and, given their individual family wealth, may avoid a bitter dispute over the sharing of their assets.